Cam operated positive clutch and brake

ABSTRACT

A clutch and brake mechanism includes a constantly rotating drive gear mounted for rotation about the driven shaft. A clutch hub is keyed to the shaft for rotation therewith and axial movement thereon, and has a lug which is to be engaged with either the drive gear or a stationary stop. A guide vane is mounted on the hub for axial movement therewith and rotation thereon, and is keyed to the drive gear for rotation therewith and axial movement thereon. The vane has a lug with a constantly rotating knife or cam blade. A nonrotatable control knife or cam blade is translated between the vane and the gear or the vane and the stationary stop to cam the vane directly and thereby shift the hub lug into engagement with either the gear or the stop.

United States Patent [72] Inventor Lewis K. Wetzel South Burlington, Vt.[21 Appl. No. 862,656 [22] Filed Oct. 1, 1969 [45] Patented May 11, 1971[73] Assignee General Electric Company [54] CAM OPERATED POSITIVE CLUTCHAND BRAKE 9 Claims, 6 Drawing Figs.

[52] 0.5. CI 192/16, 192/18R, 192/24, 192/67R [51] Int. Cl F1611 67/02[50] FieldofSearch 192/18,18 (B), 16, 24,102

[56] References Cited UNITED STATES PATENTS 2,787,355 4/1957 Dodge192/18X 3,061,059 10/1962 Kindlien etal 3,410,381 11/1968 HenshawetalABSTRACT: A clutch and brake mechanism includes a constantly rotatingdrive gear mounted for rotation about the driven shaft. A clutch hub iskeyed to the shaft for rotation therewith and axial movement thereon,and has a lug which is to be engaged with either the drive gear or astationary stop. A guide vane is mounted on the hub for axial movementtherewith and rotation thereon, and is keyed to the drive gear forrotation therewith and axial movement thereon. The vane has a lug with aconstantly rotating knife or cam blade. A nonrotatable control knife orcam blade is translated between the vane and the gear or the vane andthe stationary stop to cam the vane directly and thereby shift the hublug into engagement with either the gear or the stop.

' PATENTED um um:

sum 1 n5 3 INVENTORI LEWIS K.WETZEL, BY%LZ W HIS ATTORNEY.

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INVENTOR: LEWIS K.WETZEL,'

HIS ATTORNEY.

PATENIEU m1 1 |97| SHEET 3 0F 3 INVENTOR'. LEWIS K.WETZEL, ,QZ

HIS ATTORNEY.

CAM OPERATED IOSITIVE CLUTCH AND BRAKE BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to clutch mechanisms andparticularly to such mechanisms wherein a driven member must bedisengaged in a positive prescribed orientation and then reengaged in apositive prescribed orientation with respect to a driving member.

2. Description of the Prior Art In a high rate of fire Gatling-typeweapon wherein a cluster of barrels rotates about the longitudinal axisof the weapon and is fed with rounds of ammunition by a sprocket systemrotating about a parallel axis, it is necessary to disengage and engagethe sprocket system to the barrel cluster in positive prescribedorientations. It is desirable at the end of a firing burst toimmediately stop handing off rounds from the sprocket system to thebarrel cluster; and at the start of a firing burst to immediately andsynchronously hand off rounds from the sprocket system to the barrelcluster. A clutch which provides this function is shown in US. Pat. No.3,410,381 issued on Nov. 12, 1968 to Robert H. Henshaw et al. Thel'lenshaw et al. clutch utilizes a longitudinal stationary control knifeblade which is used to guide a shiftable clutch member to altemativelyengage either a driving member or a stationary member. The input signalis applied to the shiftable clutch member and must be of relativelysubstantial magnitude to effect this shifting of the shiftable clutchmember.

Accordingly, it is an object of this invention to provide an improvedl-Ienshaw et all type mechanism requiring an input signal of arelatively small magnitude and also incorporating positive control'during the reengagement cycle as well as during disengagement.

BRIEF SUMMARY OF THE INVENTION A feature of the invention is a clutchmechanism wherein the power required for shifting the shiftable clutchmember is obtained from the constantly rotating member which is drivenby the external power source. The mechanism further includes a drivenshaft which is to be connected to the constantly rotating member in atimed position when the clutch is engaged, and which is to be stoppedand locked in a particular stationary position when the clutch isdisengaged while the constantly rotating member continues to rotate. Theconnecting device is a sliding hub which is keyedto the driven shaft androtates with it but which can be shifted longitudinally along the shaft.This hub has a set of radial lugs, one for each of the acceptable timedpositions which alternatively engage either similar lugs on theconstantly rotating member when the clutch is engaged, or stationarylugs on the stationary housing when the clutch is disengaged-The hub isshifted longitudinally along the driven shaft by interaction between aset of rotating knife blades and a nonrotating, but, upon command,longitudinally shiftable, control knife blade. The rotating knife bladesextend radially from an additional hub which is attached through abearing to the sliding hub so that it can rotate freely with respect tothe sliding hub, but must move longitudinally therewith. This additionalhub is keyed to the constantly rotating member so that it rotates withthe member but can shift longitudinally with respect to said member.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features andadvantages of this invention will be apparent from the followingspecification thereof taken in conjunction with the accompanying drawingin which:

FIG. 1 is an exploded perspective view of a clutch mechanism embodyingthis invention;

FIG. 2 is a longitudinal cross section through the clutch mechanism ofFIG. I when engaged;

FIG. 3 is a longitudinal cross section through the clutch mechanism ofFIG. 1 when disengaged;

FIG. 4 is a top view of the clutch mechanism of FIG. 2;

FIG. 5 is a top view of the clutch mechanism of FIG. 3; and

FIG. 6 is a schematic diagram showing the knife blade interengagements.

THE PREFERRED EMBODIMENT The clutch mechanism includes a housing 10, aconstantly rotating member 12 here shown as a drive gear (turning in thedirection A), and a driven shaft 14 suitably journaled as at 14a, 14b.In a Gatling-type weapon, the drive gear might receive its power fromthe rotating barrel cluster, and the driven shaft might drive theammunition feed sprocket assembly. The driven shaft I4 includes aportion having a circular cross section and a portion 18 having twodiametrically opposed flat surfaces 20. Two longitudinally spaced-apartsets 22, 24, or pairs of diametrically opposed detent cups are formedinto the shaft portion 18.

The .drive gear 12 includes a hub portion 26, a web portion 28, a gearring portion 30, and an intermediate hub portion 32 projectinglongitudinally from the web portion. A plurality of sets of notches 34are provided, one for each desired locking position. Each set includes adeep, leading notch portion 36, having a leading face 38 and a trailingface 40, and a shallow, trailing notch portion 42 having a leading rampface 44 and a trailing face 46. The hub 26 is journaled to the shaftportion 16 by a two-piece bearing 48.

A clutch hub assembly 50 is disposed on the driven shaft portion 18; andincludes a sliding hub 52 and a vane 54.-The sliding hub 52 has a hubbody 56 having a central bore 58 with a cross section mating with andthereby keyed to the shaft portion 18. Four locking arms or lugs 60extend radially from the hub body, each having a respective trailingface 62. The vane 54 includes a hub portion 64 from which four arms orlugs 66 extend radially, each having a knife edge 68 formed into itsleading face. The hub portion 64 is journaled to the sliding hub portion56 by a two-piece bearing 68 and is captured thereto by a disc 70mounted to the hub by four machine screws 72. Two diametrically opposedradial bores are provided on the hub body 56 and are threadedrespectively to receive two spring-loaded ball detent assemblies 74. Theball detent assemblies are adapted to alternatively engage either cupset 22 or 24. Thus the hub assembly 50 is held in either the fullyengaged or fully disengaged positions with respect to the shaft I4. Thehub 52 is free for longitudinal movement with respect to the shaft 16,subject to being detented at either cups 22 or 24, but is constrainedagainst rotation with respect to the shaft.

The housing 10 has a rotary solenoid mounted to its exterior. Thearmature 82 extends through the housing and has one end of an arm 84fixed thereto. The distal end of the arm has a slot 86. A slide bar 88is keyed for reciprocation'to the interior of the housing. One end ofthe slide bar a pin 90 which is engaged by the slot 86. The distal endof the slide bar has a knife blade wedge portion 92 extending therefromand adapted to interfere with the knife blade ends 68 of the vane arms66. A spring 94 is coupled between the arm 84 and the housing 10 to biasthe wedge portion 92 towards the ring gear 30. The housing also includesa projecting block 96 having a shoulder cutout 98 which is adapted toabut and halt the leading faces 62 of the lugs 60 when the hub 52 isshifted away from the ring gear 30 as shown in FIGS. 3 and 5, and toclear the lugs when the hub is shifted toward the ring gear, as shown inFIGS. 2 and 4.

A complete cycle of engagement and disengagement may be described asfollows:

I. Assume a present state of disengagement. The drive gear 12 isrotating continuously, and the vane 54, whose arms 66 are respectivelycaptured in the slots 36 of the drive gear 12 is also rotatingcontinuously. The clutch hub 52 is remote from the drive gear 12 and onelug 60 is locked against rotating by the stop shoulder 98.

2. The solenoid is energized to move the control knife blade wedge;92away from the drive gear 12. As the wedge moves laterally, threeinteractions are possible:

a. lf the leading edge of the knife blade 68 of the next adjacent arm 66of the continuously rotating vane 54 has passed'the leading edge of thecontrol wedge 92 before the control wedge has reached the plane of theleading edge of the vane, as shown in FIG. 6A, the rotating vane knifeblade will cam the control wedge back against the force of the solenoidas shown in FIG. 68, until the knife blade has passed the control wedge.Then the solenoid will be able to continue to move the control wedgeaway from the drive gear as shown in FIG. 6C to its engagement affectingposition, abutting the shoulder 102, before the arrival of the next vanearm, as shown in FIG. 6D.

if the next adjacent rotating vane knife blade has passed the controlwedge completely, the solenoid will be able to move the control wedgeaway from the drive gear to its engagement affecting position before thearrival of the next vane arm.

c. If the next adjacent rotating vane knife blade and the control wedgemeet edge-on they must pass to one side or the other, to interact eitheras (a) or (b) above.

3. When the control wedge has completed its travel away from the drivegear and is in its engagement affecting position, a side of the wedgeserves as a camming surface for the next adjacent rotating vane knifeblade to longitudinally shift the vane towards the drive gear. Since thehub 52 and the vane 54 are keyed against relative longitudinal movement,the hub 52 also must shift longitudinally towards the drive gun, so thatits locked lug 60 shifts away from the stop shoulder 98. When the lockedlug has been shifted completely away from the stop shoulder 98 by thecamming interaction between the control wedge and the vane knife blade,the lugs are respectively fully aligned with the bearing faces 46 whichengage and rotate the lugs and the integral therewith hub and the keyedthereto shaftThe spring-loaded detents S8 engage the cups 24 to preventlongitudinal oscillation of the hub.

4. To disengage the clutch, the control signal is removed from thesolenoid and the return spring 94 starts to move the control knife bladewedge 92 towards the drive gear 12. As the wedge moves laterally thethree interactions described above at 2(a), (b) and (c) are possible.

5. When the control wedge has completed its travel towards the drivegear and is in its disengagement affecting position, abutting theshoulder 102, the other side of the wedge serves as a camming surfacefor the next adjacent rotating vane knife blade to longitudinally shiftthe vane away from the drive gear. Since the hub 52 and the vane 54 arekeyed against relative longitudinal movement, the hub 52 also must shiftlongitudinally away from the drive gear, so that each of its engagedlugs 60 shift away from its respective bearing face 46. When the lugshave been shifted completely away from the bearing faces, therebydecoupling the hub 52 from the drive gear 12, one lug 60 abuts the stopshoulder 98 and halts rotation of the hub 52. The spring-loaded detents74 engage the cups 22 to prevent longitudinal oscillation of the hub.The drive gear 12 and the vane 54 continue their rotation, the drivenshaft 14 is stationary.

In the event that relatively high rotational inertias are to be startedand stopped it may be desirable to incorporate springloaded buffers (notshown) in the lugs on the sliding hubs or the stop shoulder 98 tocushion the affect of the high accelerations involved.

To prevent inadvertent engagement from handling or vibration, a blockingsurface 106 is effectively provided on the rotating driven gear whichprevents longitudinal shifting of the hub from the disengaged positionat all rotational positions of the drive gear except in the area ofnormal engagement, during which times the longitudinal position of thehub is controlled by the interaction of the control wedge and the knifeblades. A similar blocking surface 108 is effectively provided on thehousing to prevent disengagement of the clutch except where controlledby interaction between the knife blades.

If desired to preclude backlash on disengagement, a springloaded dog,not shown, may be provided on the housing adjacent to the stop surface98, which is cammed away as the dog approaches the surface and whichthen snaps in behind the dog to lock it against the surface.

lclaim:

l. A clutch mechanism comprising:

an elongated shaft journaled for rotation;

a clutch member mounted on said shaft for rotation therewith and forreciprocal longitudinal movement therealong;

an externally powered drive member supported for rotation about saidshaft;

stationary means;

first lug means disposed on said drive member;

second lug means disposed on said stationary means;

third lug means disposed on said clutch member and adapted at a firstlongitudinal station of said clutch member on said shaft to engage saidfirst lug means whereby said drive member drives said shaft and at asecond longitudinal station of said clutch member on said shaft toengage said second lug means whereby said stationary means halts saidshaft; and

actuation means including:

vane means coupled to said clutch member for longitudinal movementtherewith along said shaft but free for rotation relative to said clutchmember, and coupled to said drive member for rotational movementtherewith but free for longitudinal movement relative thereto, said vanemeans having a lug extending therefrom with a knife edge distal portion,

a knife edge member mounted to said stationary means and moveable to andbetween a first and a second station,

said knife edge member when disposed at said first station beingdisposed in the path of said vane lug knife edge distal portion whensaid third lug means is engaged with said first lug means and adapted toengage and cam said vane lug knife edge distal portion longitudinallytowards said second lug means whereby said third lug means disengagessaid first lug means and engages said second lug means, and

said knife edge member when disposed at said second station beingdisposed in the path of said vane lug knife edge distal portion whensaid third lug means is engaged with said second lug means and adaptedto engage and cam said vane lug knife edge distal portion longitudinallytowards and first lug means whereby said third lug means disengages saidsecond lug means and engages said first lug means.

2. A clutch mechanism according to claim 1 wherein:

said drive member is provided with a plurality of equally angularlyspaced apart first lug means;

said clutch member is provided with like plurality of equally angularlyspaced apart third lug means; and

said vane means is provided with a like plurality of equally angularlyspaced apart lugs with respective knife edged distal portions.

3. A clutch mechanism according to claim 1 wherein said drive membercomprises a gear and said first lug extends longitudinally therefrom.

4. A clutch mechanism according to claim 2 wherein:

said drive member comprises a gear housing an annular hub extendinglongitudinally therefrom and spaced from said shaft,

each of said first lug means being provided by a longitudinal notch. insaid hub.

5. A clutch mechanism according to claim 4 wherein each of saidlongitudinal notches in said hub includes a first portion adapted toreceive a respective lug of said vane means and a second portion adaptedto receive a respective third lug means of said clutch member.

6. A clutch mechanism according to claim 5 wherein each of saidlongitudinal notches has a ramp surface leading thereinto.

7. A clutch mechanism according to claim 1 further including controlmeans resiliently coupled to said knife edge 6 edge member beyond saidfirst and second stations' 9. A clutch mechanism according to claim 1further includin g means effective to preclude longitudinal movementofsaid 1 vane means during certain angular distances of rotation andineffective during the remaining angular distances of rotation.

1. A clutch mechanism comprising: an elongated shaft journaled forrotation; a clutch member mounted on said shaft for rotation therewithand for reciprocal longitudinal movement therealong; an externallypowered drive member supported for rotation about said shaft; stationarymeans; first lug means disposed on said drive member; second lug meansdisposed on said stationary means; third lug means disposed on saidclutch member and adapted at a first longitudinal station of said clutchmember on said shaft to engage said first lug means whereby said drivemember drives said shaft and at a second longitudinal station of saidclutch member on said shaft to engage said second lug means whereby saidstationary means halts said shaft; and actuation means including: vanemeans coupled to said clutch member for longitudinal movement therewithalong said shaft but free for rotation relative to said clutch member,and coupled to said drive member for rotational movement therewith butfree for longitudinal movement relative thereto, said vane means havinga lug extending therefrom with a knife edge distal portion, a knife edgemember mounted to said stationary means and moveable to and between afirst and a second station, said knife edge member when disposed at saidfirst station being disposed in the path of said vane lug knife edgedistal portion when said third lug means is engaged with said first lugmeans and adapted to engage and cam said vane lug knife edge distalportion longitudinally towards said second lug means whereby said thirdlug means disengages said first lug means and engages said second lugmeans, and said knife edge member when disposed at said second stationbeing disposed in the path of said vane lug knife edge distal portionwhen said third lug means is engaged with said second lug means andadapted to engage and cam said vane lug knife edge distal portionlongitudinally towards and first lug means whereby said third lug meansdisengages said second lug means and engages said first lug means.
 2. Aclutch mechanism according to claim 1 wherein: said drive member isprovided with a plurality of equally angularly spacEd apart first lugmeans; said clutch member is provided with like plurality of equallyangularly spaced apart third lug means; and said vane means is providedwith a like plurality of equally angularly spaced apart lugs withrespective knife edged distal portions.
 3. A clutch mechanism accordingto claim 1 wherein said drive member comprises a gear and said first lugextends longitudinally therefrom.
 4. A clutch mechanism according toclaim 2 wherein: said drive member comprises a gear housing an annularhub extending longitudinally therefrom and spaced from said shaft, eachof said first lug means being provided by a longitudinal notch in saidhub.
 5. A clutch mechanism according to claim 4 wherein each of saidlongitudinal notches in said hub includes a first portion adapted toreceive a respective lug of said vane means and a second portion adaptedto receive a respective third lug means of said clutch member.
 6. Aclutch mechanism according to claim 5 wherein each of said longitudinalnotches has a ramp surface leading thereinto.
 7. A clutch mechanismaccording to claim 1 further including control means resiliently coupledto said knife edge member for moving said member between said first andsecond stations.
 8. A clutch mechanism according to claim 1 furtherincluding means for precluding longitudinal movement of said knife edgemember beyond said first and second stations.
 9. A clutch mechanismaccording to claim 1 further including means effective to precludelongitudinal movement of said vane means during certain angulardistances of rotation and ineffective during the remaining angulardistances of rotation.